I have one major introducer, hiddenbear. Through his work I've ended up meeting a whole bunch of people, who have then branched out. It's a little weird though because HB and I had a lot of overlap and by all rights should have met years prior.

On the whole though I would say I'm usually the center. I meet a lot of new people on my own and am pretty good about keeping up connections (generally speaking, though not always obviously), and doing introductions. I love meeting new people, so it happens a lot.